Promethazine is a medicine used to help with allergy symptoms, reduce or prevent nausea and vomiting, or provide sedative or pain-relieving effects after surgery. It blocks histamine receptors. Promethazine DM is a combination medicine used to treat cough, stuffy nose, runny nose, and sneezing caused by colds or allergies. Promethazine DM is for use in adults and children at least 2 years old. Promethazine DM may also be used for purposes not listed in this medication guide. Subscribe to receive new product updates, special offers, and the latest water methanol injection tuning tips and technical articles. Many people turn to medications to find relief, and one option often prescribed by doctors is promethazine cough syrup. This medication is commonly used to manage symptoms like coughing, sneezing, and runny nose, particularly when caused by allergies or colds. ProMeth Signature Series 4 Cylinder Direct Port With Elbow Nozzle Holders (Ubend-It) ProMeth Signature Series 4 Cylinder Direct Port With Split Block, Check Valves & Straight Nozzle Holders (Pre-Bent) Promethean Action is a political movement dedicated to defying oligarchy & unleashing the fire of human creativity! Get our free newsletter. Zero Spam. Voters felt the pain. Too few could see the productive future beyond it. Promethazine, sold under the brand name Phenergan among others, is a first-generation antihistamine, sedative, and antiemetic used to treat allergies, nausea, and vomiting. Promethazine is an antihistamine medication that prevents and treats the symptoms of an allergic reaction. It can also help you relax, go to sleep and relieve nausea, vomiting or pain before or after procedures. In addition, it can prevent and treat motion sickness. The brand name of this medication is Phenergan®. What is this medication? Histamine can cause itching, sneezing, runny nose, and watery eyes. It can sometimes close up the bronchial tubes (air passages of the lungs) and make breathing difficult. Promethazine is also used to prevent and control motion sickness, nausea, vomiting, and dizziness. Promethazine is used to treat allergy symptoms such as itching, runny nose, sneezing, itchy or watery eyes, hives, and itchy skin rashes. It also prevents motion sickness, and treats nausea and vomiting or pain after surgery. It is also used as a sedative or sleep aid.